tax invoice

The screen of my phone broke and in order to get it repaired i needed cell c or csurance to send me the tax invoice as this is a replacement phone. I called their call centre and was transfered from one person to the other and every single person claimed the next could help me. I then actually drove to csurance (finrite) to get my tax invoice and still nothing. I went to the branch where i collected the replacement phone and still nothing. I cant fix the screen of my phone because no one in the company keeps a paper trail of tax invoices. Cell c has proven that they are unorganized and unprofessional.